Aurin dyestuff.



4 UNITED OFFICE.

MAX WEILER. OF ELBEREELD, GERMANY, ASSIGNOR T0 FARBENFABRIKEN VORM. FRIEDR. BAYER & 00., OF ELBERFELD, GERMANY, A CORPORATION OF GEIRJVIANY.

AURIN DYESTUFF.

No Drawing.

Specification of Letters Patent.

Application filed April 26, 1910.

Patented. Dec. 13, 1910. Serial No. 557,718.

To all whom it may concern:

Be it known that I, MAX WETLER, doctor of philosophy, chemist, citizen of the German Empire, residing at Elberfeld, Germany, have invented new and useful Iinprovements in New Dyestuffs, of which the following is a specification.

My invention relates to the manufacture and production of new dyestuffs (aurin dicarboxylic acids) which are obtained by condensing in the presence of oxidizing agents methylene oxycarbo-Xylic acids, especially methylene (ii-salicylic acld and methylene di-ortho-cresotinic acid with phenols with an unoccupied para position to the hydroxyl group, which phenols contain in ortho position to the hydroxyl group one or two indifferent groups.

The new dyes are dark powders soluble in dilute caustic soda lye generally with a red color, dyeing wool from acid baths generally from red to violet shades, which can be chromed on the fiber.

In order to illustrate the new process more fully the followin example is given, the parts being by weight: 21.1 parts of niethylene-di-ortho-crcsotinic acid and 13 parts of 2.6-dichlorophenol are stirred at from 2045 C. together with 320 parts of a strong sulfuric acid and the necessary quan tity of nitrosyl sulfuric acid until the quantity of the dyestufi' produced does no longer increase and the evolution of nitrogen oXids ceases. The product of the reaction is oured on ice and the dyestufi is filtered oif. l t is a reddish-brown powder which dyes Wool a scarlet-red which turns intense red on chroming.

Other oxidizing agents such as nitric acid, |n1tro compounds, concentrated or fuming sulfuric acid may be used. Methylene-disalicylic acid can be used instead of methylene-di-ortho-cresotinic acid and other of the above mentioned phenols may be e.m ployed, c. g. 2.6-dibromophenol, 2.6-nitromethylphenol, 2.G-dibromo-3-methyl-phenol, fifi-dichloropheno1.

The new dyestuffs can also be dyed on chromed wool or on wool together with chromium compounds.

1. The herein described dyestuffs obtainable from methylene-oxycarboxylic acids and phenols in which the para position to the hydroxyl group is unoccupied which dyestuffs are dark powders soluble in dilute caustic soda lye generally with a red color, dyeing wool from soil baths generally from red to violet shades, which can be chromed after dyeing, substantially as described.

2. The herein described new dyestuff obtainable from methylene-(ii-ortho-cresotinic acid and 2,6-dichlorophenol, which is a reddish-brown powder soluble in dilute caustic soda lye with a red color, dyeing wool scarlet-red shades, which turn intense red on chroming, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

MAX W'EILER. [L. s.]

Witnesses OTTO Kola IG, VALTER VONNEGUT. 

